//=============================================================================
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//=============================================================================
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// 2009,2010,2012 Robert Finch
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// 2009,2010,2012 Robert Finch
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// Stratford
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// Stratford
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// robfinch<remove>@opencores.org
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// robfinch<remove>@opencores.org
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//
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//
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// WRITE_BACK state
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// WRITE_BACK state
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// - update the register file
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// - update the register file
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//
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//
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//
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//
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// This source file is free software: you can redistribute it and/or modify
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// This source file is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published
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// it under the terms of the GNU Lesser General Public License as published
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// by the Free Software Foundation, either version 3 of the License, or
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// by the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// (at your option) any later version.
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//
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//
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// This source file is distributed in the hope that it will be useful,
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// This source file is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// GNU General Public License for more details.
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//
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//
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// You should have received a copy of the GNU General Public License
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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//
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//
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//=============================================================================
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//=============================================================================
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//
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//
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if (wrregs)
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if (wrregs)
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case({w,rrr})
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case({w,rrr})
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4'b0000: ax[7:0] <= res[7:0];
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4'b0000: ax[7:0] <= res[7:0];
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4'b0001: cx[7:0] <= res[7:0];
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4'b0001: cx[7:0] <= res[7:0];
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4'b0010: dx[7:0] <= res[7:0];
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4'b0010: dx[7:0] <= res[7:0];
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4'b0011: bx[7:0] <= res[7:0];
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4'b0011: bx[7:0] <= res[7:0];
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4'b0100: ax[15:8] <= res[7:0];
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4'b0100: ax[15:8] <= res[7:0];
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4'b0101: cx[15:8] <= res[7:0];
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4'b0101: cx[15:8] <= res[7:0];
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4'b0110: dx[15:8] <= res[7:0];
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4'b0110: dx[15:8] <= res[7:0];
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4'b0111: bx[15:8] <= res[7:0];
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4'b0111: bx[15:8] <= res[7:0];
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4'b1000: ax <= res;
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4'b1000: ax <= res;
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4'b1001: cx <= res;
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4'b1001: cx <= res;
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4'b1010: dx <= res;
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4'b1010: dx <= res;
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4'b1011: bx <= res;
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4'b1011: begin bx <= res; $display("BX <- %h", res); end
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4'b1100: sp <= res;
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4'b1100: sp <= res;
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4'b1101: bp <= res;
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4'b1101: bp <= res;
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4'b1110: si <= res;
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4'b1110: si <= res;
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4'b1111: di <= res;
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4'b1111: di <= res;
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endcase
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endcase
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// Write to segment register
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// Write to segment register
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//
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//
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if (wrsregs)
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if (wrsregs)
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case(rrr)
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case(rrr)
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3'd0: es <= res;
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3'd0: es <= res;
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3'd1: cs <= res;
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3'd1: cs <= res;
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3'd2: ss <= res;
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3'd2: ss <= res;
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3'd3: ds <= res;
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3'd3: ds <= res;
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default: ;
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default: ;
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endcase
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endcase
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